The disclosure relates generally to optical fibers, and more particularly to methods of of removing coating material from one or more optical fibers, along with fiber optic connectors and cable assemblies related to such methods.
Optical fibers are useful in a wide variety of applications, including the telecommunications industry for voice, video, and data transmissions. In a telecommunications system that uses optical fibers, there are typically many locations where fiber optic cables that carry the optical fibers connect to equipment or other fiber optic cables. To conveniently provide these connections, fiber optic connectors are often provided on the ends of fiber optic cables. The process of terminating individual optical fibers from a fiber optic cable is referred to as “connectorization.” Connectorization can be done in a factory, resulting in a “pre-connectorized” or “pre-terminated” fiber optic cable, or the field (e.g., using a “field-installable” fiber optic connector).
Regardless of where installation occurs, a fiber optic connector typically includes a ferrule with one or more bores that receive one or more optical fibers. The ferrule supports and positions the optical fiber(s) with respect to a housing of the fiber optic connector. Thus, when the housing of the fiber optic connector is mated with another connector or adapter, an optical fiber in the ferrule is positioned in a known, fixed location relative to the housing. This allows an optical connection to be established when the optical fiber is aligned with another optical fiber provided in the mating component (the other connector or adapter).
Ferrules bores typically have a size that is only slightly larger than a “bare” optical fiber to provide the fixed positional relationship mentioned above. The term “bare” is used because optical fibers, which may be glass or plastic, are normally surrounded by one or more protective coatings/layers. For example, many optical fibers are provided with a soft coating from acrylic directly on the optical fiber material (e.g., glass) for moisture protection. Furthermore, many of these “coated” optical fibers are surrounded by a tight buffer layer/coating from a harder plastic (e.g., PVC or polyolefin) to provide physical protection. With such tight buffered cables, removal of both the tight buffer coating and acrylic coating is typically required prior to inserting the optical fiber into a ferrule bore.
Both one-step removal processes (i.e., the tight buffer coating and acrylic coating being removed together) and two-step removal processes (i.e., the tight buffer coating and acrylic coating being removed separately) are known. These processes often involve mechanical stripping, but may additionally or alternatively involve chemical stripping, hot gas stripping, and laser stripping. Each of these techniques presents its own challenges. For example, mechanical stripping includes physically removing material from the optical fiber with a semi-sharp edge of one or more blades, which has the potential to damage the optical fiber and/or can require time-consuming inspection and replacement procedures for the blades. Chemical stripping uses chemicals to dissolve material intended to be removed, but the chemicals may require extensive safety measures and procedures to protect the environment. Hot-gas stripping uses a heated jet of gas (e.g., nitrogen or air) to melt and remove material, which can be difficult to control and may result in considerable debris. Laser stripping involves using one or more laser beams to vaporize or ablate material, but can require complex and expensive equipment to distribute the laser energy around the optical fiber in a desired manner.
In addition, once both the tight buffer coating and acrylic coating are removed from an end section of an optical fiber using any of the above-mentioned methods, the optical fiber may be vulnerable to damage. A stripped (i.e., bare) optical fiber may be damaged merely by being brought into contact with particulates, which may scratch or damage an exterior surface of the optical fiber where coating material has been removed. Any stripping process completed prior to insertion of the optical fiber into a ferrule must be managed carefully so that the stripped optical fiber is not damaged prior to being protected within the ferrule.